1. Field of the Invention
This invention relates to fittings installed in swimming pool walls for returning filtered water into the pool. More specifically, it relates to pool water return fittings installed in poured concrete swimming pool walls.
2. Background & Description of the Related Art
In-ground swimming pools can be built using a variety methods and materials. Pool walls can be made from fiberglass-reinforced plastic, vinyl-lined metal or wood frames, spray-applied gunite, poured concrete and concrete lined with a polymeric sheet material. The present invention is intended for use in swimming pool walls created by pouring a wet concrete mixture into a mold consisting of interlocking wall forms held in place with wall ties including such concrete walls lined with a liner.
Typically, poured concrete swimming pool walls are made by building a mold for the walls utilizing engineered modular forms. The forms are interconnected with one another to outline the sides of the pool wall. The wall is created by filling the space between the modular forms with wet concrete and allowing the concrete to cure. The forms are then removed and the cured concrete wall remains. The forms are modular or sectional in nature which means that they are interconnected as necessary to form a continuous mold for the poured wall. Each section of the wall is molded by an opposing pair of forms. An inner form molds the inside face of the wall and an outer form molds the outside face of the wall. The paired forms are positioned in an opposing and spaced apart configuration, the space between the forms being the desired wall thickness.
The forms are held at the desired wall thickness by wall ties spanning the space between the forms and connecting the inner form to its paired outer form. The wall ties typically connect to the forms by engaging pins projecting horizontally from the vertical sides of each form. Each tie engages a pin on an inner form and a corresponding pin on the paired outer form. The wall ties prevent the paired forms from moving closer together or further apart when concrete is poured into the space between the forms. Typically, a wall tie remains embedded in the concrete wall when the forms are removed and the part of the tie projecting out of the wall is removed so the end of the tie is generally flush with the face of the wall.
Many swimming pools utilize a filtration system for keeping the pool clean and free of debris. The filtration system generally takes the form of a pumped system that removes water from the pool and draws or pushes the water through a filter. The filtered water is returned to the pool through the filtered water return system. The return system piping connects to a return fitting installed in the pool wall which allows the return water to flow back into the pool.
A pool water return fitting typically comprises a flanged tubular body with a round face plate that connects the pool return water system to the swimming pool. The flange of the fitting installs nearly flush with the interior face of the pool wall, and the face plate attaches to the flange with the pool liner and a gasket located between the face plate and flange. A problem with currently available pool water return fittings is that they are not long enough to span the width of a poured concrete wall. Spanning the width of the wall is necessary to ensure the fitting can be connected to the return system piping on the back of the pool wall after the concrete has cured and the forms have been removed. Because currently available fittings are not long enough to span the width of a poured concrete wall, a makeshift extension must be created and attached to the fitting if such a wall is desired. The pieces in a typical return fitting extension are a male adapter screwed into the return fitting, a short section of pipe glued to the male adapter, and a slip coupling glued to the short section of pipe. These extensions are often made on site with leftover fittings and piping, and because each extension is made on an as-needed basis, they lack uniformity in size and quality.
When a fitting and extension assembly is mounted in a poured concrete form system it can only be secured from one end. This is because the fitting is the only part of the assembly designed to receive a threaded fastener which is the common method for mounting the apparatus prior to pouring the concrete. Typically, the return fitting is screwed to the inner form which leaves the extension unsupported and cantilevered out from the form, making it susceptible to damage from poured concrete. Pouring concrete on top of the cantilevered extension can cause it to become vertically or horizontally angled and misaligned. Also, because the return fitting must be screwed to the inner form, mounting holes must be drilled in the form which results in permanent damage to the form.
If the extension ends up being slightly shorter than the distance between the forms, concrete may surround the unsupported end of the extension and incase it inside the wall, or concrete could leak into the extension's interior. Conversely, if the extension is too long, it can break when squeezed between the forms. Even if the extension is presumed to be the proper length, duct tape is usually wrapped around the end of the extension as a precautionary measure to prevent concrete from inadvertently leaking into the assembly.
It is undesirable to use custom-made return fitting extensions every time a poured concrete wall is constructed. Creating extensions adds time and expense to a swimming pool construction project. The extensions also face potential damage from the concrete pouring process. What is needed in the swimming pool industry is a return fitting designed for installation in poured concrete walls.